Former Alaska attorney general Dan Sullivan announces he is joining the Republican race for U.S. Senate on Tuesday morning, October 15, 2013, at the Dena&#xE2;&#x20AC;&#x2122;ina Civic and Convention Center in Anchorage. His wife Julie Fate Sullivan as at left.

Lt. Gov. Mead Treadwell speaks with former Alaska state Senate President Drew Pearce as he launched his U.S. Senate campaign at his headquarters in Anchorage on Thursday, Sept. 12, 2013.

Bill Roth

WASHINGTON -- A television advertisement in Alaska, where Democratic Sen. Mark Begich is seeking re- election, criticizes federal government inaction and shows a candidate by a snowmachine saying: "Washington will figure out that I don't take no for an answer."

The ad isn't from one of Begich's Republican competitors. It's from the senator's own campaign.

The spot, which highlights Begich's work to expand domestic oil production in energy-rich Alaska, shows how he and other Democrats seeking Senate seats in Republican-leaning states are downplaying their ties to Washington, D.C., and President Barack Obama in a midterm election that historically disadvantages the party holding the White House.

In the 2012 election, Obama lost by 14 percentage points in Alaska, one of six states Senate Democrats are defending where the president's margin of defeat was at least 13 points. Those races are raising expectations among Republicans that they have a strong shot at retaking control of the chamber. They need a net win of six seats to oust the Democratic majority.

Republicans are seeking to nationalize those races by linking the Democrats to Obama and the Affordable Care Act as a way of motivating voters in what typically are lower-turnout elections since the presidential race isn't on the ballot.

In addition to common themes, those Senate contests are experiencing an unprecedented explosion of early TV ads -- funded by the same group of super-political action committees and nonprofits that can raise money in unlimited amounts to influence elections.

Begich, his top Republican challenger and nine Outside groups already have aired ads more than 6,900 times, according to New York-based Kantar Media's CMAG, which tracks advertising.

"We're attracting a great deal of outside money and outside focus on our campaigns," Jerry McBeath, a political scientist at the University of Alaska Fairbanks, said in a telephone interview. "And in tight races, this additional contribution of outside funds, which currently favors the Republican Party more than the Democratic Party, can be critical."

More ads have run in the Alaska contest than in all but four other Senate races, CMAG data show. North Carolina, which leads with more than 11,100 ads, has 13 times the population of Alaska, the nation's fourth least-populous state.

The burst of early ads in Alaska comes more than four months before the Aug. 19 Republican primary and seven months before the Nov. 4 general election. It's a lot of television in a state where just 256,000 votes were cast in the 2010 Senate election, fewer than were tallied in Manhattan in last year's New York City mayoral election.

SUPER-PAC ADS INUNDATE ALASKANS

Americans for Prosperity, a nonprofit group favoring limited government that was founded by the billionaire industrialists Charles and David Koch, has paid for two ads that have run in Alaska 1,453 times, more than any other group or candidate. The group was first on the air in Alaska, introducing a spot in November linking Begich to Obama's health-care law.

Americans for Prosperity's second ad, which ran in February and March, again attacked Begich on health care and also accused the incumbent of supporting a carbon tax. American Energy Alliance, a nonprofit group promoting more domestic energy production, made the same claim in an ad that began running April 2. PolitiFact rated the carbon-tax claim as "mostly false."

Begich initiated his advertising campaign last month with a commercial portraying the Koch brothers as out-of-state billionaires disconnected from Alaska's needs.

Begich's wife narrates another ad, one that includes footage of his late father, Nick Begich, who was on a plane that disappeared in 1972 as he campaigned for re-election to the U.S. House. The ad came amid public interest in the search this year for Malaysian Air Flight 370.

In Begich's third ad, the senator is shown snowmobiling in remote northern Alaska and touting his effort to facilitate drilling in Alaska's National Petroleum Reserve over bureaucratic resistance from Obama's Environmental Protection Agency and the U.S. Army Corps of Engineers.

"He's delivered when it comes to energy development, he's protected fishermen's jobs and he's willing to go the extra mile to listen to folks, visit with them and speak with them," Max Croes, a spokesman for Begich's campaign, said in a telephone interview.

Begich is getting outside help from Put Alaska First PAC, a super-PAC that's aired three ads, two of which attack former Department of Natural Resources Commissioner Dan Sullivan's Alaska bona fides.

Put Alaska First raised $790,500 through March from just five donors, including 82 percent of its total from Senate Majority PAC, a super-PAC run by political advisers to Majority Leader Harry Reid of Nevada. Put Alaska First got $100,000 from a limited liability company linked to Kirkland, Wash.-based Fishermen's Finest Inc., a fishing company.

American Crossroads, a super-PAC founded with help from Republican Karl Rove, has intervened in the primary on behalf of Sullivan, who's raised the most money and also has the backing of the Washington-based Club for Growth, which seeks to slash spending, taxes and regulation. The Sullivan campaign didn't return a message seeking comment for this article.

Sullivan is seeking the party nomination against Lt. Gov. Mead Treadwell and Joe Miller, a lawyer aligned with the limited-government tea party movement who defeated Sen. Lisa Murkowski in a 2010 Republican primary before Murkowski won the general election as a write-in candidate.

Sullivan, a Marine and former State Department official under President George W. Bush, is "tireless in the defense of his country," former Secretary of State Condoleezza Rice said in the American Crossroads ad defending Sullivan from Democratic attacks.

American Crossroads siding with Sullivan over Treadwell and Miller shows how some Republican officials are identifying the strongest general-election candidates and want to avoid burdensome primaries that could hamper the party's ability to win a majority.

Sullivan released his first ads late last month, one touting his military background and a second featuring his wife.

Democratic groups have attacked Sullivan and other Republican Senate candidates early in the 2014 campaign because they "want to define the GOP candidates before they define themselves -- like the Obama campaign did to Mitt Romney in 2012," Rove wrote April 3 in the Wall Street Journal.